Train-control system



E. 1. BLAKE. TRAIN CONTROL SYSIEM. APPLICATION FILED AUGJI. 1915.

1,316,263. PatenwdSept. 16,1919.

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mmcum INVENTOR BY QM \JIMUJ... 4110mm El 1 TRAIN CONTROL SYSTEM.

APPLICATION men AUGJI. ms.

' ,3 1 6 ,26 3 Patenwd Sept. 16, 1919.

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ELI JUDSON BLAKE,

OF WESTFIELD, NEW JERSEY, ASS IGNOB TO HAL-LSWITCH 86 SIGNAL 00., A CQ-RPORATION OF MAINE.

TRAIN-CONTROL SYSTEM.

Specification of Letters Patent.

Patented Sept. 16, 1919.

Application filed August 11, 1915. Serial No. 45,078.

To all whom it may concern.-

Be it known that I, ELI Jonson BLAKE, of Westfield, in the county of Union and in the State of New Jersey, have inventeda certain new and useful Improvement in Train-Control Systems, and do hereby declare that the following is a full, clear, and exact description thereof.

My invention relates particularly to systems for controlling the operation of trains by a method which in its general nature is electrical.

In constructing train control systems where automatic stopping devices are used it is necessary to locate the actuating devices for the same at such a point as to bring the train to rest before reachin the entrance of an occupied block. In the case where the actuating devices are located at a certain definite point for all trains, it is necessary for them to be located to the rear of the entrance to the braking distance for the fastest train. Furthermore, it has been found necessary previously to locate the stop signal for the engine man in the rear of the actuating devices, as it is not desired to remove the responsibility from the engine man to operate the controlling devices of the train to bring the same to a stop when the signal indicates that the train should be stopped. The minimum headway between the trains upon a iven track is thus very much increased owing to the presence of the signal and actuating devices a considerable distance in the rear of the entrance to each of the blocks and the increase in the minimum headway is the distance between the stop signal and the entrace to the block. The amount of trafiic that can be carried by track in such a system is therefore correspondingly reduced.

One object of my invention is to provide a train control system which will not interfere with the control of the train by the engineer provided he is governed by the signals, and which will not therefore relieve the engineer of the responsibility of following the signals in the operation of the train; nor will it require any increase of minimum headway over that which is required with non-automatic control; but which, in the event of the engineers disregarding a stop signal will automatically bring the train to rest near the point indicated by the stop signal, irrespective of the speed at which the tram is traveling. Another object of my invention is to provide means for stopping the tram automatically if predetermined speeds are exceeded over particular parts or the Whole of the track. Another object is to provide signals on the train for the guidance pf the engineer, which signals may be used in addition to, or in place of, fixed signals along the way as ordinarily employed heretofore.

I have therefore found it desirable to proyide a system in which automatic means will intervene to bring the train to rest only in the event of the engineers failin to keep the train under such control as will permit of bringing it to rest at the point where safety requires it to come to rest, or failing to reduce the speed of the train to a safe value where such reduction is required, inasmuch as by this means a train can be ermitted to run, under proper control, c ose to the entrance of an occupied block, and the use of the automatic control will involve no increase in the minimum headway between trains. The arrangement of my system is such, furthermore, that the actuating devices for limiting the speed of the train may be located according to the peculiar conditions of the railroad at the particular point. For example, the location will take into consideration the direction of slope of the grade and the extent of the grade of the track. No system of train control having the actuating devices located only at the maximum braking distance from the entrance to a block could fully take account of these conditions,

even though the maximum braking distance might be determined with reference to grades, and even though apparatus on the train might be arranged to control the brakes in accordance with the speed of the train on level track for the change in braking distance reguired by grades will not be the same at di erent speeds, especially if the grade changes between the point of brake application and the stopping oint. With a system of this character, furt ermore, limitation of the speed of the trains may be made continuous over the entire track if desired. Furthermore, my system is such that safety is indicated only when all of the devices and circuits controlling the safety indication are intact. The parts are, in other Words, predisposed to the indication of danger and return automatically to such 1ndication in case the power supply or any other part of the system fails. This 1s a distinct advantage over prior systems different] arranged, especial] y systems which de end on indications of safety received on y at particular locations along the track. In my system safety 15: indicated cont1nuously by current which flows over the entire block and a fraction of a block in advance of the train.

While my invention is capable of embodiment in many different forms, for the purpose of illustration I have shown only certain forms thereof in the accompanying drawings, in which Figure 1 is a diagrammatic side elevation of a railway and car operated in accordance with my invention;

Fig. 2 is a side elevation of a portion of the track and car showing one form of tripper that might be used;

Fig. 3 a rear elevation of the same;

Fig. -l is a side elevation of a portion of track and car showing another form of tripper;

Fig. 5 is a rear elevation of the same;

Fig. 6 is a. side elevation of a portlon of a track and car showing a form of tripper comprising an interrupted magnetic circuit.

F1g. 7 is a rear elevation of the same Fig. 8 is an enlarged detail of the timing device;

Fig. 9 is a diagrannnatic plan new of the track and the wheels of the car showing an arrangement of the devices on the car for controlling the car from the track;

In the drawings I have shown railway rails 1 and 2 located on ties 3 on which rails a car 4 is adapted to run in the direction of the arrow as shown in Fig. 1. Assuming that. an arrow 5 in Fig. 1 indicates the point Where it is desired to stop the car or train, in the rear of this point I locate a number of single trippers 6, 6, 6", and just in rear of the point 5 I locate a double tripper 7. The distance between each tripper and the next tripper in advance is the distance that would be traversed in a given period of time by a car passing the latter tripper at the highest speed which would permit of brin ing it to rest at the point 5. For exampe, if the period chosen is five seconds, and if the double tripper 7 is located at a sufiicient distance from the point 5 .for stopping the train from a speed of five miles per hour, the distance between the t-rippers 7 and 6 is the dis tance that the train must travel in five seconds to pass the tripper 7 at five miles per hourand if the location thus determined for the tripper 6 is at a suliicient distance from the point 5 for bringing the train to rest from ten miles per hour, then the tripper 6" will be located in the rear of the tripper 6 by the distance thatthe train must travel, in five seconds to pass the trippcr (3 at ten miles per hour. in the same manner successive trippers are located at increas ing distances back at least to a point which will allow sullicient braking distance for the fastest train.

In locating the trippers as described, aceount should be taken of possible acceleration of the train, so that even though the speed of the train may increase during the passage from one tripper to the next, the speed at the latter trippcr will not exceed the speed corresponding to its distance from the stopping point unless it has traversed the distance in less than the chosen interval of time. Account should also be taken of all characteristics of the trains and roadway which affect the distance required for stopping, such as the ellectivcncss of brake eipiipment and the direction and extent oi grades.

From the foregoing it will be understood that a train approaching a stopping point at any constant speed will pass trippcrs at progressively decreasing intervals; and that when the point is reached where brakes must be applied, the interval will have decreased to the minimum interval in accordance with which the trippers were located. But if the train approaches the stopping point safely under control, that is if the speed is properly reduced as the stopping point is approached, no two trippers will be passed within five seconds.

If, instead of a full stop. it is required to enforce any given speed limit over any portion. of the track, trippers may be located along this portion of the track at distances corresponding to the time interval on which the spacing of trippers is based; and in the approach to this limited speed section other trippers may be located in the manner al ready described for the approach to stopping points, back to the point of brake application for the fastest trains. As shown in Figs. 2 and 3 the trippers 6, 6 6*, may be comprised of bars 8 attached to the ties 3, or as shown in Figs. 4 and 5, there may be plates 9 attached to the sides of the rails, or as shown in Figs;- 6' and 7 there may be sections 10 of manganese steel which is non-- magnetic so as to thereby break a magnetic circuit. In the case of the trippers 8 and 9 the actuation of the controlling devices on the train may be merely by a pivoted follower 11 supported on the truck or trucks of the train. In the case of the non-magnetic rail section 10 the actuation may be accomplished by breaking the magnetic circuit between the poles of an electromagnet 12 carpivoted to the truck,

rled on an arm 13 also and normally pulled downwardly by the steel rails in opposition to the force of a spring 14 connected from the movable end of the arm 13 to the truck.

Assuming that the type of follower shown in Figs. 4 and 5 is used, the follower 11 has an arm 15 which is connected by a link 16 to an arm 17 of a timing device, as shown in Fig. 8. This timing device comprises a heavy oscillating wheel 18 supported upon a pivot 20 which also pivotally supports the arm 17. The wheel 18 carries a stop 19 which is adapted to cooperate with one end of the lever arm 17 in such a manner that when the follower 11 comes in contact with one of the trippers 9 the projection 19 is given an upward impulse thus rotating the wheel 18 which, however, is drawn back again to its ori inal position by a spiral sprlng 21 attached at its inner end to the center of the wheel 18 and at its other end to some fixed support on the car. The period of oscillation of the wheel 18 is such that the same period of time is required for a one-half revolution thereof and its return to its normal position as the interval of time separating the trippers 6, 6, 6", and 7 in the case of a train moving at the maximum desired speed. For example, if the trippers have been located at distances corresponding to five second intervals for a train moving at the maximum speed permissible at each point, the oscillating wheel 18 would have a period of five seconds. As seen in Fig. 8 there is provided a catch 22 which normally rests against the outer face of the projection 19, said catch being pivotally supported upon a valve lever 23 attached to a valve 23 adapted to exhaust air from the brake pipe 24 of the braking system. The catch is nor mally spring pressed against the outer face of the projection 19 by a spring 25 connecting one end of the catch 22 to the arm 23. lVhen the follower 11 comes in contact with one of the trippers 9 it actuates the oscillatin wheel 18 as previously described without in uencing the position of the catch 22 and therefore without affecting the valve 23 in the air pipe 24. In a case were the train is operating within the limits of speed established by the trippers 6, 6, 6" and 7 the projection 19 will return to its initial and normal position after actuation before the train has reached the next succeeding tripper. The 0 eration of the wheel 18 by this next succee ing tripper under these circumstances will again have no effect upon the catch 22 where the train is operating at the required speeds. If, however, the train should not reduce its speed as required b the position of the trippers 6, 6, 6" and the end of the arm 17 will enga e the catch 22 thus moving the same upwar ly and operating the valve in the pipe 24 so as to throw on the brakes. The operation is such therefore that one movement of the arm 17 for each period of the wheel 18 does not operate the brake valve, but where the movements of the arm 17 are more frequent than the periods of the wheel 18 the brake valve will be operated. This explains also the purpose of the double stop 7 located just before the final stopping point of the train, as the double movement of the arm 17 will result in throwing on the brakes in the manner just described, to bring the train to a stop, irrespective of its s eed. The timing mechanism I have descri ed is only one of many well known devices which could be used to accomplish the same end, namely the opening of a valve whenever two impulses are received within a fixed interval.

When the blocks are clear and free from danger my system is arranged in such a manner as to indicate this fact to the engine man, and also in such a manner as to close a valve 26 so as to prevent actuation of the brakes in case the valve attached to the lever 23 is operated. This is accomplished in the following manner. The tracks are supplied with an alternating current flowing in the direction of the arrows as shown in Fig. 9, that is to say, by passin alon one rail. 2, through the wheels and ax es and then returning by the other rail 1. Transformers 27 are provided consisting of cores 28 surrounding the axles at the front of the car and coils 29, the coils 29 on a particular truck being connected togetherbyawire 30, and being connected together also by a wire 31, which wires are in circuit with the Winding of a relay 41*. While I have shown transformers surrounding the first two axles pf the train, they may be applied to any number of axles in the train. The use of more than one transformer lessens the possibility of interruption of the circuit due to imperfect contact between the wheels and rails. It will be understood that the alternating current passing along the rail 2 will divide, part passing throu h the front axles, which are surrounded by t e transformer cores, and part continuing along the rail to axles in the rear.

The relay which is responsive to periodic current is provided with a contact finger 48 in a circuit 42 including the battery 37. Through the contact finger 43 of this relay, and through a wire 45, current passes from the battery 37 to a lamp 44, returning to the battery through a wire 46. A branch circuit in multiple with the lamp 44 and including a magnet coil 47 controlling a lever 48 on the valve 26 passes through wires 49 and 50. Thus the lamp 44 will be lighted and the! valve 26 will be held closed if a suitable alternating current is passing through the axles embraced by the transformer cores 28, and not otherwise. The lamp 44 serves as a signal to the engineer, indicating when lighted that the track ahead is clear to the end of the next block in advance. The valve 26 serves, when the track is clear, to cut oil the connection between the air-brake system and the valve 23, which would otherwise cause the train to stop automatically at the entrance of every block, regardless of the condition of the block.

Another circuit, including a lamp 51, passes from the battery 37 through wires 42, 52 and 5%, through catch 22 and, if the oscillating wheel 18 is in its normal position, through a conducting plate 55 which is carried on and insulated from the projection 19 of the wheel 18, to lamp 51, through wires 53, 50 and 4.6 back to battery 37. The lamp 51 serves to indicate to the engineer the approach of the train to a point where the train must stop if the lamp 441 is out. It will burn continuously so long as the maximum speed may be safely maintained. As the stopping point is approached it will be extinguished as each tripper is passed for a period equal to the period of the oscillating wheel 18, then lighted until the next tripper is passed. The duration of the periods of light will indicate to the engineer how nearl he is approaching the point at which bralies will be automatically applied. This will occur if the speed of the train is maintained until the alternating periods of light at the lamp 51 have diminished to nothing.

As shown in Fig. 9, the track may be divided into blocks 60 and 61 comprising rails which are separated by insulating joints 63. In this connection I provide transformer 65 for supplying current 'from the wires 56 and 57 respectively to the block 60. It is to be understood however that instead of using transformers I may use any other source for the esired current. The current from the transformer 65 is supplied to the block 60 through a relay contact finger 66. The cont-act in the relay 66 is controlled by a coil 67 in a wire 68 bridging the block immediately in front of the block 60 so that should the current in said block in front of the block 60 fail, the contact in the relay 66 would be broken and the current supplied from the wires 56 and 57 would no longer be supplied to the block 60. It therefore follows, as pointed out above that when a block inadvance of the block which a train is approaching is clear, the passage of the current through the particular relay will maintain the passage of the current over the wires 56 and 57 to the block which the train isapproaching thus showing through the various signal devices already described when the train reaches the block which it has been approaching that the train may enter the block in question. Should, owever, another train'be in the block which the first train is approaching, the wheels of the other train would short-circuit the current in the block thus breaking the contact in the relay in at vancc of the first train and diseontinum the supply of current from the wires 5 and 57 to the block in which this train is located. It will therefore be seen that when a train enters the block immediately in the rear of a block that is occupied by another train, current derived from the wires 56 and 57 will cease to flow through the axles of the first-mentioned train, thus causing the light 44 to go out, and operating the valve 26 so as to permit the brake system to be thrown on by the operation of the valve attached to the lever 20 The brake system will be thrown on in this manner only, however, in the case where the engine man does not himself operate the train in such a manner as lo de crease the speed as rapidly as required and to bring it to a stop at the required point in advance of the occupied block.

lVhile I have described my invention above in detail, I wish it to be understood that many changes may be made therein without departing from the spirit of my invention.

I claim 1. In a train control system, a car, a way on which the car travels, successive actuating devices on the way, controlling devices on the car actuated thereby C0111 arising a brake controlling means, means or disengaging said devices from the brake apparatus, said disengaging means comprising a swinging element having a definite period, and an electric circuit containing a signal, said circuit including a contact controlled by the swinging element.

2. In a train control system, a car, a way on which the car travels, successive actuating devices on the way, controlling devices on the car actuated thereby comprising a brake controlling means, means for disengaging said devices from the brake apparatus, said -idisenga ing means comprising a swinging element having a definite period,

the same as the period of travel of a train at the maximum speed permitted from one actuating device to the next actuating de vice, and an electric circuit containing a signal, said circuit including a contact controlled by the swinging element.

3. In a train control system, a car, a way on which the car travels, successive actuating devices on the way and controlling devices on the car actuated thereby, comprising means for stopp'in the train de endent on the time consume in passage etween successive actuating devices, and a signal on the car ada ted .to indicate the condition of the centre apparatus.

4. In a train control system, a car, a Way on which the car travels, successive actuating devices on the Way and controlling devices on the car actuated thereby, comprising means for stopping the train dependent on the time consumed in passe e etween successive actuating devices an a signal on the car adapted to indicate the condition of the control apparatus, said signal being controlled by an electric circuit which is Uopie: or thin potent may be obtained tor the cents each, by addressing the -cansed to vary for a definite period as each actuating device is passed.

In testimony that I claim the foregoing I have hereunto set m hand.

ELI J DSON BLAKE. Witnesses:

LAURA DE C. ABBo'rT, 'FRANcns A. PUGH.

"Commissioner 01 Iatents.

Washington, D. 0. 

